Seismic Response And Damage Analysis Based On Wavelet Analysis Of Mega-frame Structure

The mega-frame structure system which is a type of structure system with a promising future.But currently the theoretical and experimental studies of mega-frame are few,many issues remain tobe studied in depth. In this paper, with the support of National Natural Science Foundation majorresearch project "super high-rise mega-frame structure and energy of seismic response analysis ofresearch", wavelet analysis method is used to carry out damage research on reinforced concrete.Damage and seismic performance were studied form component level to the mega-frame structuralsystem, the theoretical formula had been verified from the numerical simulation to the experimentalstudy. The following conclusions and research results can be reached.(1) Based on current domestic seismic design codes, a201m super-high reinforced concretemega-frame structure was designed by PKPM-SATWE. Based on some reasonable simplification,aelasto-plastic finite element analysis model was built. The three dimensional elasto-plastic dynamicresponse and damage of the structure were analyzed. Meanwhile, it can verify the rationality of thedesign which is conducted by PKPM-SATWE.(2) In order to explore some further methods to improve the seismic performances of themega-frame, a TMD device is set up in the top of the mega-frame. Accordingly, a finite elementnumerical simulation model is established to analyze the elasto-plastic dynamic time-historyresponses and damage of this structure and study its damping effect.(3) In order to verify the rationality of the finite element numerical simulation and earthquakedamage mechanism of mega-frame, for the201m high mega-frame composite structure, areduced-scale geometric ratio of1:25scale model of shaking table was designed and fabricatedaccording to similarity theory, and a reduced-scale TMD equipment was designed and fabricated atthe top of this reduced-scale model. Through the shaking table test conducted in State KeyLaboratory for Disaster Reduction in Civil Engineering at Tongji University, a more abundant resultsabout the comparison test between mega-frame and damping structure were obtained, and thenexperimental results were compared with numerical simulation results.(4) From the elasto-plastic time-history analysis of the mega-frame structure dynamicnumerical model and shaking table test results, the seismic performance of this mega-frame structuremeets the seismic design requirements, and the TMD device has definite damping effect and thedamping effect of TMD is not only affected by the parameters of the TMD itself,but also isassociated with the ground motion characteristics.(5) A wavelet-based seismic damage model about component is proposed in the basis ofwavelet transform theory. In combination with some cyclic loading test results about a number ofshear walls,beams and columns which were conducted by our research group previously,this seismic damage model for the components were used to analyze the damage of these components.The calculating results of this seismic damage indexes and the experimental phenomenon were ingood agreement.(6) A method can be used for model parameter identification of single degree of freedom,multi-degree of freedom, mega-frame composite structure of finite element numerical simulationmodel and shaking table. The wavelet-based and general method (fitting the admittance circle) werecompared, the results show that the wavelet-based can provide accurate identification of modalparameters of the structure to meet the project accuracy requirements.(7) A damage identification index was proposed in the basis of wavelet packet node energy, andmulti-degree of freedom structural damage was identified, the results show that the index can betteridentify structural damage location and time.(8) A damage identification index λkwas proposed, and an eight-story reinforced concrete framestructure, mega-frame composite structure of finite element numerical simulation model and shakingtable damage were identified, the results present that the damage that the index can better identifystructural damage.